Edexcel Chemistry IGCSE

PAPER CHROMATOGRAPHY Diagram Showing the Paper Chromatography of Ink and Plant Dye USE: To Separate Substances that have Different Solubilities in a Given Solvent (E.g Different Coloured Inks that have been Mixed to Make Black Ink) METHOD: Pencil Line is Drawn on Chromatography Paper and Spots of Ink / Dye is Placed on it Paper is Lowered into a Bucket of Solvent, Allowing the Solvent to Travel Up the Paper, Taking some of the Coloured Substances with it Allow Chromatography to Occur until the Solvent Reaches the Top of the Paper RESUTS: As the Solvent Travels Up the Paper, Different Substances will have Different Solubilities so will Travel at Different Rates, Causing the Substances to Spread Apart This will show the Different Components of the Ink / Dye - http://igcse-chemistry-2017.blogspot.ae/2017/07/113-practical-investigate-paper.html

R f VALUES: Used to Identify the Components of Mixtures s The R f value of a particular compound is always the same →This allows industries to use chromatography to identify the compounds in a mixture. EQUATION : s Rf Value =     Distance Moved by Compound    ÷     Distance Moved by Solvent

PAPER CHROMATOGRAPHY - COMPOSITION OF A MIXTURE Diagram Showing the Composition of an Ink using Paper Chromatography COMPOSITION OF A MIXTURE: Chromatograms will Show the Composition of a Mixture as the Different Coloured Substances (Components) will Spread Apart as they will Have Different Solubilities so will Travel at Different Rates A Pure Substance will Only Produce One Spot on the Chromatogram during Paper Chromatography In the Diagram Above, Red, Blue and Yellow are Three Pure Substances, whilst the Sample on the Left is a Mixture of All Three - https://igcse-chemistry-2017.blogspot.ae/search?q=1.11

SIMPLE DISTILLATION Diagram Showing the Simple Distillation of a Mixture of Salt and Water USE: To Separate a Liquid from a Solution (E.g Water from a Solution of Salt Water) EXPLANATION: Solution is Heated and Water Vapours will Rise and Evaporate Water Vapours will Pass through the Condenser, where it Cools and Condenses, turning into a Liquid that will be Collected in a Beaker After All the Water is Evaporated from the Solution, the Solute will be Left Behind FRACTIONAL DISTILLATION Diagram Showing the Fractional Distillation of a Mixture of Ethanol and Water USE: To Separate Two or More Liquids that are Miscible with One Another (E.g Ethanol and Water from a Mixture of the Two) EXPLANATION: Solution is Heated at Temperature of Substance with the Lowest Boiling Point This Substance will Rise and Evaporate, and Vapours will Pass through a Condenser, where it Cools and Condenses, turning into a Liquid that will be Collected in a Bea

Impure compounds have a range of melting points and boiling points, as the different substances they contain melt or boil at different temperatures. They may even interfere with each other's melting and boiling points.  However, pure compounds have definite melting points and boiling points. The presence of an impurity usually: Lowers the melting point Raises the boiling point The greater the amount of an impurity, the bigger the differences from the true melting point and boiling point. -BBC Bitesize

Element : A substance that cannot be broken down into simpler substances by  chemical means . An  element  is composed of atoms that have the same atomic number. Compound:   A substance formed when two or more  chemical  elements are chemically bonded together. Mixture:   A  mixture  is a combination of two or more pure substances in which each pure substance retains its individual  chemical  properties.